Insights into electrochemiluminescent enhancement through electrode surface modification

Abstract

This version is available at https://strathprints.strath.ac.uk/42668/ Strathprints is designed to allow users to access the research output of the University of Strathclyde. Unless otherwise explicitly stated on the manuscript, Copyright © and Moral Rights for the papers on this site are retained by the individual authors and/or other copyright owners. Please check the manuscript for details of any other licences that may have been applied. You may not engage in further distribution of the material for any profitmaking activities or any commercial gain. You may freely distribute both the url (https://strathprints.strath.ac.uk/) and the content of this paper for research or private study, educational, or not-for-profit purposes without prior permission or charge.Any correspondence concerning this service should be sent to the and PVP is poly(4-vinylpyridine). Through a combination of ground state electrochemical studies and ECL measurements, the ECL efficiency for each film is determined. This study reveals that despite a dramatic influence in charge transfer rates between metal centres, as observed for the conducting polymer, mediated through the conducting polymer backbone, a corresponding increase in ECL efficiency is not always observed. The degree of communication between the adjacent excited state metal centres are an important consideration for ECL enhancement however self quenching, luminophore distribution and film porosity must also be considered.

High efficiency electrochemiluminescence from polyaniline:ruthenium metal complex films

“…(1), the current increased linearly with increasing ν 1/2 and the slope yielded a D CT value of 2.6 ± 0.9 × 10 −10 cm 2 s −1 . Significantly, this value is approximately an order of magnitude faster than that reported previously for structurally related ruthenium complexes bound within non- conducting polymers, e.g., nafion-[Ru(bpy) 3 ] 2+ and [Ru(bpy) 2 (poly-4-vinyl pyridine) 10 ] 2+ , where D CT values of 2.3 ± 0.8 × 10 −11 and 9.2 ± 1.1 × 10 −11 cm 2 s −1 , respectively, were observed [2]. Taking the layer thickness into account with this charge transport diffusion coefficient, all of the Ru 3+ luminophores can be regenerated within approximately 3.5 s. Throughout the ECL analysis the films showed good stability and the ECL intensity changes by less than 10% over a 4 h period suggesting that the composite film is strongly bound to the electrode and that leaching of the metal complex is relatively slow.…”

“…ECL detection in bioassays [1] offers significant advantages, including inherent sensitivity, since unlike optically driven emission, it does not need a light source. Furthermore, it also offers temporal and spatial control over the chemiluminescent reaction, making it a powerful approach for multiplexed assays especially when the luminophore is confined to an electrode surface [2]. However, identifying the optimum matrix for immobilising the luminophore is challenging since fast regeneration of the luminophore is desirable, but equally quenching by the matrix and the electrode surface needs to be minimised [3].…”

A Cholesterol Biosensor Based on the NIR Electrogenerated-Chemiluminescence (ECL) of Water-Soluble CdSeTe/ZnS Quantum Dots

“…24 Combined with the specificity of the ECL reaction, these attributes produce a technique that is ideally suited for detecting low concentration target analytes in complex matrices with a good signal to noise ratio. [25][26][27][28] However, at the time of writing there does not appear to be any work based on the ECL of near-infrared (NIR) QD films for the detection of cholesterol. The benefit of such a system is that emission above 800 nm reduces signal interference from whole blood samples, an issue that can affect detection systems that use emitters in the visible region.…”

Electrochemiluminescence platform for the detection of C-reactive proteins: application of recombinant antibody technology to cardiac biomarker detection

“…The electrocatalytic oxidation of TPA by ruthenium metal centres is a common mechanism which can result in the production of an ECL response when the oxidised co-reactant (TPA) and the oxidised ruthenium metal centre of the label react. [11,12] Figure 1 shows the dependence of ECL emission over a CRP concentration range (5 fg mL -1 to 600 ng mL -1 ). The ECL emission observed at 1.2 V versus a silver/silver chloride (Ag/AgCl) reference electrode, corresponds with previous reports for a ruthenium metal centre and the shape of the curve is in accordance with ruthenium based ECL dynamics.…”

“…It is equivalent to the charge diffusion in redox polymers involving an electronhopping process from site to site where transport of both electrons and charge compensating counter ions occurs simultaneously. [11,13] The rate of electron transfer k decays exponentially with the distance r between redox centres in the transition state. A bimolecular rate of electron transfer for Ru 2+ * to Ru 3+ of ~10 6 M -1 s -1 was reported previously, highlighting the fact that the excited state can be quenched efficiently by Ru 3+ species in close proximity to the excited state Ru 2+ *.…”